Drainage plane flashing material

ABSTRACT

A flashing material and method provides a moisture drainage passage to prevent water damage to buildings. The flashing material includes: (a) a planar portion for providing a drainage plane for the passage of moisture along a plane defined by said planar portion, wherein said planar portion includes a porous sheet capable of permitting the passage of water therethrough along the drain plain, and/or a water impervious sheet having a surface defining said drainage plane; (b) a water-impervious layer which is bonded on a first side to the planar portion; and, preferably (c) a layer of adhesive applied to a second side of the water-impervious layer. The flashing material is particularly useful for installing a portal such as a window or door in an opening in a wall, or for sealing joints in roofs, for installing skylights and similar such uses.

BACKGROUND

1. Field of the Invention

The present application relates to building construction, and particularly to a material and method for providing a flashing system incorporating a drainage plane for the removal of moisture

2. Background of the Art

Prevention of water damage is an ongoing task of the building construction industry. In particular, exterior moisture such as rain, when in long term contact with the interior structure of a building, can cause rotting of wood and growth of mold. The rotting of wood leads to structural damage and very expensive repairs. Molds can harm the health of the occupants of the building by causing allergies and other ailments.

Entry of moisture can occur over time by a combination of several mechanisms. For example, after several years buildings can settle. Their shapes become distorted and no longer square or level. Window joints and sealants can separate and openings can then develop in the flashing. Wind driven rain moving at an angle off vertical can seep in through the sides of the flashing. Moreover, moisture can be generated from inside the house by the inhabitants, for example, by cooking, laundering, bathing, and other such activities. This moisture can then migrate through the walls to the exterior where it can condense. Without removal this condensate can become another cause of water damage.

Today the entire residential and commercial construction marketplace is threatened by the runaway costs of litigation and claims management due to the effects of mold and water damage to parts of the building envelope affected by the use of the present state of the art in flashing systems. Organizations like AAMA are attempting to develop minimum standards for self adhering flashing and are focused on the present generation of design ignoring the need for an adequate drainage plane at the building/opening interface.

To prevent water damage the construction industry uses moisture barriers which are impervious to water. Such moisture barriers include polymeric sheets (e.g., TYVEK™ brand polyolefin sheet), asphalt saturated felt or paper, and the like. Flashing is applied around windows to prevent water seepage through the joint between the window frame and the wall in which it is installed. Flashing can include sheets of metal, polymer films, coatings of bitumen, silicone and other sealants, face films and other materials well known in the construction art. The problem with conventional flashing materials and methods is that once water does enter behind trim and cladding it has no easy way to drain or escape. The lack of a drainage plane in the flashing materials then becomes a disadvantage by trapping moisture between exterior trim, cladding and siding.

The existing flashing systems employ a mass of heavy yet pliable material to block water and conform to uneven surfaces. The typical chemical structure limits the range of temperature performance and installation. They commonly experience compatibility problems with sealants used around the window and door openings used to seal gaps and seal the window in place. These products in their use of all impermeable materials and solid face films fail to create a drainage plane for water to migrate down the edges of the window and fail to introduce air to aid in evaporation.

What is needed, and what the present invention provides, is a drainage plane in the immediate proximity of the window, door, or joint at the most vulnerable part of the building envelope for the removal of moisture.

SUMMARY

Provided herein is a flashing material and method for providing a moisture drainage passage to prevent water damage to buildings and to alleviate conditions which promote the growth of mold and mildew. The flashing material includes: (a) a planar portion for providing a drainage plane for the passage of moisture along a plane defined by the planar portion, wherein said planar portion includes (i) a porous sheet capable of permitting the passage of water therethrough along the drain plain, and/or (ii) a water resistant sheet having a surface for providing said drainage plane; (b) a water-impervious layer which is bonded on a first side to the planar portion; and, (c) a layer of adhesive applied to a second side of the water-impervious layer.

The flashing material is particularly useful for installing a portal such as a window or door in an opening in a wall, or for sealing joints in roofs, for installing skylights, weather stripping, deck installation, and similar such uses.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are described below with reference to the drawings wherein:

FIG. 1 is a perspective view of the flashing material of the invention;

FIGS. 1A and 1B are alternative embodiments of the flashing material;

FIG. 2 is a front elevational view illustrating the use of the flashing material for sealing the periphery of a window; and

FIG. 3 is a side elevational view illustrating an alternative use of the flashing tape of the invention in connection with a window sill.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

Referring now to FIG. 1, in one embodiment the flashing material of the invention, i.e., flashing tape 100 includes a first layer of porous polymeric sheet 110 capable of permitting the passage of water therethrough along the plane of the sheet so as to provide a drainage plane for water. Preferably the porous polymeric sheet 110 is an open cell foam. A preferred open cell foam suitable for use in the invention is available from Foamex International Inc. of Linwood, Pa. under the designations 2AZUF and P4B. Alternatively, the porous polymeric sheet 110 can comprise a woven or non-woven fibrous layer.

A second layer 120 of polymeric sheet is bonded to the first layer 110, for example by flame bonding or adhesive bonding or any other suitable bonding method. Second layer 120 is impervious to water and is preferably a closed cell polymeric foam. A closed cell polymeric foam suitable for use in the invention is available from Sekisui Voltek LLC under the designation Volara 3TS, 5TS, GEO or GG. Alternatively, second layer 120 can be a water-impermeable sheet such as polymeric film or metal foil.

The flashing tape 100 of the invention preferably further includes a layer of 130 of adhesive applied to a second side of the second layer 120. The adhesive is preferably a high performance pressure sensitive acrylic adhesive to facilitate adherence to a substrate such as a wall or sheet of flashing or house wrapping material. A pressure sensitive adhesive suitable for use in the present invention is available in a 1-sided or 2-sided coated VOLTEK Volara 5TS foam from Adchem Co. under the designation MTLG-190.

Preferably the flashing tape 100 includes a release film 140 which is removed prior to application of the tape 100 to a substrate.

Optionally, the flashing tape 100 can further include another pressure sensitive adhesive layer 150, as well as an associated removable release liner 151 overlying the adhesive layer 150, on an upper surface of the open cell foam first layer to permit adhesion of a layer of water resistant flashing or house wrapping material on top of the flashing tape 100. The flashing or house wrapping material can be a sheet of polyolefin film, preferably spun-bonded polyethylene or spun-bonded polypropylene (e.g., TYVEK® brand), metal or foil sheet or other conventional material. A preferred house wrapping material for use in conjunction with the flashing tape of the invention is a polyolefin sheet house wrap having at least one engineered surface textured with embossed nondirectional channels for permitting aeration and water drainage, and which is commercially available from Valeron Films under the designation VORTEC™.

Referring now to FIGS. 1A and 1B, embodiment 100A of the flashing tape includes the porous polymeric sheet 110 bonded to the water-impermeable second layer 120, which has an adhesive layer 130. A water resistant house wrap 160 is bonded to the porous sheet 110. The house wrap has at least one textured surface 161 with embossed nondirectional channels which provide a drainage plane along the surface 161 to permit the drainage of moisture. Thus, drainage is provided by both the porous polymeric sheet 110 and the textured surface 161 of the house wrap. Embodiment 100A of the flashing tape can also include a release liner 140 adjacent to adhesive layer 130 and an additional adhesive layer 150 on the opposite side of the flashing tape 1 φA with second release liner 151 as illustrated in FIG. 1.

FIG. 1B illustrates a flashing tape embodiment 1000B wherein the house wrap 160 is bonded directly to the water impermeable second layer 120 such that the drainage plane is provided by the textured surface 161 of the house wrap. Embodiment 100B of the flashing tape can also include a release liner 140 adjacent to adhesive layer 130 and an additional adhesive layer 150 on the opposite side of the flashing tape 100A with second release liner 151 as illustrated in FIG. 1.

The flashing tape 100 of the invention is typically about 4 to 9 inches wide and stored in rolls. The preferred thickness ranges from about 0.030 inches to about 0.080 inches. It should be flexible, but not so compressible as to collapse the open cell foam under normal pressures, which would interfere with the functioning of the drainage plane provided by the tape 100. Any dimensions suitable for the use described herein can be used.

Optionally, the first or second polymeric layers 110 and/or 120 can have one or more pesticide incorporated therein such as, for example, agents for inhibiting the growth of mold or mildew, as well as insecticides, antimicrobials and/or other biocides. The pesticide can be incorporated into the polymer itself or can be introduced into the open cell foam after fabrication. Compatible organic and inorganic pesticides for protecting against damage by mildew, fungi, mold, termites and other wood eating insects are known.

Referring now to FIG. 2, use of the flashing tape 100 is illustrated wherein window 200 is mounted into an appropriately sized opening in wall 300 of a building. In a typical window installation procedure the house wrap is folded into the sides and bottom of an opening in the wall into which the window is to be installed. The window is then inserted. Appropriate sealants (e.g., silicones or other suitable compounds) can be used to fill the gap in the joint between the window and wall to secure the window. Typically, the window will have a flange extending one or two inches further than the edge of the opening. The flange can be secured to the structure with fasteners (nails, screws, etc.). In one procedure the flashing tape 100 is applied over the flange and the wall so as to overlap the edge of the flange. Optionally, the flashing tape 100 can be applied around the periphery of the opening in accordance with recognized installation procedures available from AAMA, AIA, WDMA and ASTM prior to installation of the window so as to provide a drainage plane underneath the flange. Optionally, the flashing tape 100 is applied both under and over the window flange. Other flashing material, house wrap, etc. or trim boards can be applied over the flashing tape 100.

In an alternative embodiment as shown in FIG. 3, a sloped piece 210, preferably fabricated from a composite wood or plastic, is mounted on the sill between wall 300 and window 200. A low permeability film 170 of, for example, polyethylene of EPDM membrane, is adhesively bonded to the top of the sloped piece 210 and arranged to wrap around the corner of the sill and overlap the water resistant house wrap 165 mounted to the exterior surface of the wall 300. A porous polymeric sheet 115 fabricated from an open cell foam or fibrous sheet as described above in connection with layer 110 is mounted to film 170 to provide a drainage plane. An open cell foam, for example, will provide a barrier to air intrusion while allowing water to escape from the building structure. Preferably, house wrap 165 has at least one textured surface with embossed channels to provide a drainage plane, as described above with respect to VORTEC™ brand house wrap.

While the above description contains many specifics, these specifics should not be construed as limitations of the invention, but merely as exemplifications of preferred embodiments thereof. For example, the flashing tape 100 of the invention can be used in any application in which it is advantageous to provide a drainage plane for moisture such as automotive, commercial or residential construction. Those skilled in the art will envision many other embodiments within the scope and spirit of the invention as defined by the claims appended hereto. 

1. A flashing material which comprises: (a) a planar portion for providing a drainage plane for the passage of moisture along a plane defined by said planar portion, wherein said planar portion includes i. a porous sheet capable of permitting the passage of water therethrough along the drain plain, and/or ii. a water resistant sheet having a surface defining said drainage plane; (b) a water-impervious layer which is bonded on a first side to the planar portion; and, (c) a layer of adhesive applied to a second side of the water-impervious layer.
 2. The flashing material of claim 1 wherein the porous first sheet comprises an open cell polymeric foam material.
 3. The flashing material of claim 2 wherein the second sheet comprises a closed cell polymeric foam.
 4. The flashing material of claim 1 wherein the adhesive is a pressure sensitive adhesive.
 5. The flashing material of claim 4 further including a removable release liner disposed over the adhesive layer.
 6. The flashing material of claim 1 further including a second layer of adhesive applied to a surface of the first sheet opposite to the side to which second layer of polymeric sheet is bonded.
 7. The flashing material of claim 6 further including a release liner removably disposed over the second layer of adhesive.
 8. The flashing material of claim 3 wherein the second sheet of closed cell polymeric foam is bonded to the first sheet of open cell polymeric foam by flame bonding.
 9. The flashing material of claim 3 wherein the second sheet of closed cell polymeric foam is bonded to the first sheet of open cell polymeric foam by adhesive bonding.
 10. The flashing material of claim 1 wherein at least the porous first sheet further includes at least one biocide.
 11. The flashing material of claim 1 wherein the surface of the water resistant sheet is textured with embossed nondirectional channels to permit the drainage of moisture along said surface.
 12. The flashing material of claim 11 wherein the planar portion (a) comprises both the porous sheet and the water resistant sheet.
 13. The flashing material of claim 11 wherein the planar portion (a) comprises only the water resistant sheet, which is bonded directly to the water impervious layer (b).
 14. A flashing material which comprises: (a) a first layer of open cell polymeric foam; (b) a second layer of closed cell polymeric foam bonded on a first side to the first layer of open cell polymeric foam; (c) a layer of pressure sensitive adhesive applied to a second side of the second layer; (d) a removable release liner disposed on the layer of pressure sensitive adhesive.
 15. The flashing material of claim 11 further including a water resistant sheet bonded to a side of the open cell polymeric foam and having a surface with embossed nondirectional channels.
 16. A method for sealing a joint in a wall of a building comprising: attaching to a surface of the wall over or in the vicinity of the joint a flashing tape which includes, (a) a planar portion for providing a drainage plane for the passage of moisture along a plane defined by said planar portion, wherein said planar portion includes a porous sheet capable of permitting the passage of water therethrough along the drain plain, and/or a water resistant sheet having a surface defining said drainage plane; and, (b) a water-impervious layer which is bonded on a first side to the planar portion.
 17. The method of claim 16 wherein the porous sheet comprises an open cell polymeric foam.
 18. The method of claim 16 wherein the water impervious layer comprises a closed cell polymeric foam.
 19. The method of claim 16 wherein said attaching comprises adhesively bonding the flashing tape by means of a pressure sensitive adhesive.
 20. The method of claim 16 wherein the surface of the water resistant sheet is textured with embossed nondirectional channels to permit the drainage of moisture along said surface.
 21. The method of claim 16 wherein the planar portion (a) comprises both the porous sheet and the water resistant sheet.
 22. The method of claim 16 wherein the planar portion (a) comprises only the water resistant sheet, which is bonded directly to the water impervious layer (b).
 23. The method of claim 16 wherein the joint is between a portal and an edge of the wall defining an opening configured and dimensioned to receive the portal.
 24. The method of claim 23 wherein the portal is a window. 